61665598451 has 2 divisors, whose sum is σ = 61665598452. Its totient is φ = 61665598450.

The previous prime is 61665598433. The next prime is 61665598457. The reversal of 61665598451 is 15489556616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61665598451 - 2²⁶ = 61598489587 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (61665598457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30832799225 + 30832799226.

It is an arithmetic number, because the mean of its divisors is an integer number (30832799226).

Almost surely, 2^61665598451 is an apocalyptic number.

61665598451 is a deficient number, since it is larger than the sum of its proper divisors (1).

61665598451 is an equidigital number, since it uses as much as digits as its factorization.

61665598451 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776000, while the sum is 56.

The spelling of 61665598451 in words is "sixty-one billion, six hundred sixty-five million, five hundred ninety-eight thousand, four hundred fifty-one".